1. Technical Field
The present invention relates to a DIN rail terminal block. More particularly, the present invention relates to a terminal block configured to be movably mounted on a DIN rail and including a terminal and a resilient plate that are novel in design and are ingeniously interconnected to enable good electrical connection and secure fastening.
2. Description of Related Art
A DIN rail terminal block is a terminal block movably mounted on a DIN rail and using the DIN rail as an electrode. More specifically, the terminal block is fastened and electrically connected to the DIN rail by a terminal and a resilient plate in the terminal block. As several such terminal blocks of similar functions can be mounted on the same rail to save space and facilitate wiring, DIN rail terminal blocks are in extensive use.
A conventional DIN rail terminal block typically includes a plastic housing and a conductive terminal provided in the plastic housing and configured for contacting with a DIN rail. The plastic housing is secured in position to the rail by laterally provided screws which press against the rail. However, with such a positioning mechanism, not only are the screw threads of the plastic housing likely to be damaged, but also the surface of the rail tends to be scratched. In addition, as the screws need to be tightened or loosened during the positioning process, the entire fastening operation can be time consuming. Moreover, incomplete fastening may result in cases where there are too many wires but too little space. These are the major drawbacks of the aforesaid conventional DIN rail terminal block.
Another conventional DIN rail terminal block, known as the phoenix terminal block, includes a plastic housing, a conductive terminal in the plastic housing, and a curved metal fastener in a bottom portion of the plastic housing. The metal fastener has a curved surface for contacting with a DIN rail and thereby providing electrical connection as well as resilient fastening. Nevertheless, as the metal fastener contacts the rail with a curvedly bent portion, the area of contact for electrical connection is rather small, and hence the electrical connection tends to be incomplete. Besides, the curved surface of the metal fastener is subject to wear and tear, and assembly of the terminal block is laborious. Furthermore, since the terminal and the metal fastener are supported by engagement between plastic and metal elements in the housing, high-precision molds are required for making the terminal block, which disadvantageously adds to the complexity and costs of manufacture.